1. Field of the Invention
The present invention relates to a radiation curable composition, a storing method thereof, a forming method of a cured film, a patterning method, an use of a pattern, electronic components and an optical waveguide.
2. Related Background of the Invention
As insulating films for use in LSIs and PDPs there have conventionally been used SiO2 films formed by CVD methods, and organic SOG (Spin On Glass) or inorganic SOG films formed by coating methods, because of their excellent heat resistance and electrical reliability. With insulating films of the prior art, however, it is impossible to directly form wiring grooves or contact holes, and usually a photoresist is patterned on the insulating film, followed by either dry etching with plasma or wet etching with a chemical solution, after which the film is subjected to a resist removal step or washing step to form a pattern. On the other hand, imparting photosensitive properties to an insulating film material with excellent heat resistance, electrical reliability and transparency eliminates the need for the resist material required in the steps mentioned above, thereby allowing the plasma dry etching, chemical solution wet etching, resist removal and washing steps to be omitted.
In recent years there have been proposed radiation curing polysiloxane materials with excellent heat resistance, electrical reliability and transparency. For example, in Japanese Patent Application Laid-Open No. 6-148895 and Japanese Patent Application Laid-Open No. 10-24696 there are disclosed photosensitive resin compositions comprising an alkali-soluble siloxane polymer, a photoacid generator and a solvent, from which the water and catalyst have been removed. Japanese Patent Application Laid-Open No. 2000-181069 and Japanese Patent Application Laid-Open No. 2002-72502 disclose photosensitive polysilazane compositions comprising polysilazane and a photoacid generator. Also, Japanese Patent Application Laid-Open No. 2001-288364 discloses a radiation curable composition comprising a hydrolyzable silane compound, a photoacid generator and an acid diffusion controller.